(function(win, doc) {
	//浏览器缩放时
	win.onresize = function() {
		change();
	};
	change();
	function change() {
		//320  20px
		//414  20px
		var oFs = doc.documentElement.clientWidth / (320/20);
		//设置根目录字体大小
		doc.documentElement.style.fontSize = oFs + 'px';
	}
})(window, document);
